In general, stringed musical instruments commonly comprise a body having a first end with a support for attaching one end of the strings, a second end having a support for attaching the other end of the strings and a tuning apparatus for adjusting the tension, and thus the pitch, of each of the strings. As one example, a steel guitar is a generally horizontally mounted guitar having a head end and a tail end and a plurality of strings extending therebetween. The head end is provided with a plurality of tuning keys (one for each string) to which one end of a string is secured. The tuning keys allow manual adjustment of the pitch of each string to tune the guitar. The other end of the string is secured to a bridge at the tail end of the guitar.
In addition, stringed instruments such as guitar, steel guitars, and the like, typically have more than one possible tuning. A “tuning” of a stringed instruments means the pitches assigned to the open pitch (the fundamental pitch of the properly tuned, unstopped, full string) of each of the strings on the stringed instruments. For example, the standard tuning, which is the most common tuning, of a standard, six string guitar, from lowest pitch string (top string in standard orientation of guitar) to highest pitch string (bottom string) string is E-A-D-G-B-E. However, there are a number of “alternate” tunings. For example, “drop tunings” begin with the standard tuning and then lowers (“drops”) the pitch of only a single string, or in rare cases, two strings. The dropped stringed is usually the lowest pitched (E) string, such as in the “drop D tuning” in which the lowest string is tuned down a whole step to a low D. Other alternate tunings are referred to as “open tunings” in which the open pitch of all six strings play a chord. For instance, the major open tunings give a major chord with the open strings, such as “Open A,” “Open B,” etc.
Steel guitars are generally not tuned in standard guitar tuning, but instead are tuned to an open chord, and have many, many popular tunings. The most common 6-string steel guitar tuning is the C6 tuning, which in itself has no “standard”, but rather has a number of variations. One popular C6 tuning is C-E-G-A-C-E, from lowest pitch (closest to the musician in the standard playing position) to highest pitch (furthest from the musician). All tunings shown herein are from lowest pitch to highest pitch, i.e. from thickest string to thinnest string. Several alternate tunings for steel guitar include: Open E tuning—E-B-E-G#-B-E; Open A tuning—E-A-E-A-C#-E; Open G tuning—D-G-D-G-B-D; to name a few among many more.
In the course of playing certain stringed instruments, in particular a steel guitar, a musician may desire to produce characteristic effects, and/or change the overall tuning of the instrument, by changing the pitch of one or more selected strings by adjusting the tension of the particular string(s), rather than by modifying the vibrating length of the string(s) by “fingering” on a fret board or placing a movable slide (or “tone bar” or “fret bar”) along the string(s). Changing the pitch of just selected strings allows the musician to expand the amount of tonal and chordal variation available to the musician in playing the stringed instrument.
While the tuning keys provide for relatively convenient tuning of the “open pitch” (the fundamental pitch of the properly tuned, unstopped, full string) of each string, musicians often desire to modify the open pitch of one or more strings while playing the instrument. The tuning keys are not convenient for adjusting the pitch of a string while playing for a variety of reasons. For one, the keys are not located in a convenient location for the musician to adjust manually because the musician is generally using both hands to play the instruments, with one hand strumming or plucking the strings and the other hand manipulates the strings to adjust their pitch to form desired tones. In addition, the tuning keys do not allow for a calibrated or consistent adjustment of pitch to an adjusted pitch, or consistent return to the original open pitch, but instead both changes in pitch vary with the amount of manual rotation of the key which is inherently imprecise as it depends on the manual precision of the musician.
In the past, various pitch adjusting mechanisms for adjusting the pitch of select strings of a stringed musical instruments while playing the instrument have been proposed. These pitch adjusting mechanisms generally operate by selectively increasing or decreasing the tension or pitch of a string by moving one of the secured ends of the string to either decrease the vibrating length of the string (which increases the tension and raises the pitch) or increase the vibrating length of the string (which decreases the tension and lowers the pitch). Although not limited to steel guitars, these types of pitch adjusting mechanisms have found widespread application on steel guitars.
Typical examples of pitch adjusting mechanisms for adjusting the pitch of strings on string instruments while playing, such as a steel guitar, are found in U.S. Pat. No. 3,688,631 and U.S. Pat. No. 3,390,600. These patents are expressly incorporated by reference herein in their entireties. Each of these patents discloses a pitch adjusting mechanism for adjusting the pitch of an individual string both upwardly or downwardly. The mechanisms in both of these two patents also have in common that the pitch adjusting mechanism is provided at the bridge end of the strings and the mechanisms comprise relatively complicated systems of levers, springs and linkages. In order to provide for both raising and lowering the pitch of the string with a single lever attached to the string, these mechanisms provide for a system which allows the single lever to be selectively actuated in both directions, i.e. clockwise and counter-clockwise, and also provide a means for returning the string to the open tune position (this means the normal pitch of the string without actuation of the pitch adjusting mechanism) upon de-actuation. Accordingly, the springs and lever arms of each of the parts of these mechanisms must be delicately balanced to provide proper operation and to minimize or avoid mis-tuning.
However, none of the prior pitch adjusting mechanisms allow for a simple, individually operated actuator which can adjust the pitch of multiple strings each by differing and modifiable amounts. In other words, none of the prior devices provide a simple mechanism which can adjust a first string by one amount which is modifiable, and another string by a different amount which is independently modifiable from the first string, by the operation of a single actuator, such as a single lever or pedal. For example, adjusting a steel guitar from one tuning to a different tuning may require adjusting one string a whole tone, while adjusting another string by a half tone (the term “note” is used interchangeably herein with the term “tone” when referring to the musical scale).
Therefore, there is need for a pitch adjustment device for stringed instruments which overcomes the problems associated with prior devices.